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Using the formula:
Risetime = Horizontal distance (div) x ( S W E E P T I M E / D I V
setting) x " x 1 0 M A G " v a l u e
A d j u s t t o the vertical scale
w i t h
P O S I T I O N
IslflllllWJ
Fig.
[ E X A M P L E ]
For the example s h o w n in Fig. 1 6 , the horizontal distance
is 4 . 0 divisions.
T h e S W E E P T I M E / D I V setting is 2 / / s
Substituting the given value:
Risetime = 4.0 (div) x 2 (/^s) = 8 /zs
Risetime and falltime c a n be measured by making use of
the alternate step 3 a s described below as well.
4. U s e the O
POSITION control to set the 1 0 % point to
coincide with the center vertical graduation line and
measure the horizontal distance to the point of the i n -
tersection of the w a v e f o r m with the center horizontal
line. Let this distance be D i . Next adjust the waveform
position s u c h that the 9 0 % point coincides with the
vertical centerline and measure the distance from that
line to the intersection of the waveform with the hori-
zontal centerline. T h i s distance is D2 and the total hori-
zontal distance is then D1 plus D2 for use in the above
relationship in calculating the risetime or falltime.
Using the formula:
Risetime = (D1 +D2) (div) x ( S W E E P T I M E / D I V setting) x " x
1 0 M A G " v a l u e
( 1 / 1 0 )
1
A d j u s t 9 0 % point to the center
and measure D2.
Rise time
Fig. 17
2 2
A P P L I C A T I O N
( 1 / 1 0 )
1
16
A d j u s t 1 0 % point t o t h e
center and m e s u r e D1.
[ E X A M P L E ]
For the example s h o w n in Fig. 1 7, the measured Di is 1.8
divisions while D2 is 2.2 divisions. If S W E E P T I M E / D I V
setting is 2 /us w e use the following relationship
Substituting the given value:
Risetime = (1.8 + 2.2) (div) x 2 (us) = 8 us
T I M E D I F F E R E N C E
M E A S U R E M E N T S
This procedure is useful in measurement of time differ-
ences between t w o signals that are synchronized to one
another but s k e w e d in time.
Procedure:
1. Apply the t w o signals to channel 1 and channel 2 I N -
. P U T j a c k s and select the vertical MODE s w i t c h to
D U A L choosing either A L T or C H O P mode.
Generally for l o w frequency signals C H O P is chosen
with A L T used for high frequency signals.
2. Select the faster of the t w o signals as the S O U R C E and
use the V O L T S / D I V and S W E E P T I M E / D I V controls to
obtain an easily observed display.
Set the A V A R I A B L E control to CAL.
3. Using the ^ POSITION control s e t the w a v e f o r m s to
the center of the C R T display and use the
control to set the reference signal to be coincident with
a vertical graduation line.
4. Measure the horizontal distance between the t w o s i g -
nals and multiply this distance in divisions by the
S W E E P T I M E / D I V setting.
If " x 1 0 M A G " is being used multiply this again by 1 / 1 0 .
Using the formula:
Time = Horizontal distance (div) x ( S W E E P T I M E / DIV
setting) x " x 1 0 M A G " value"
Referance signal
T i m e difference
Fig.
[ E X A M P L E ]
For the example s h o w n in Fig. 1 8, the horizontal distance
measured is 4 . 4 divisions. T h e S W E E P T I M E / D I V setting
is 0.2 ms.
Substituting the given value:
Time = 4.4 (div) x 0.2 (ms) = 0 . 8 8 m s
POSITION
(1 / 1 0 )
1
C o m p a r i s o n signal
18
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